Validation can set to Block, None or Warn. This is done from the Application.CFG file on the device by setting the ValidationWarningType in the CountWorkflow.See below for example.
The application file is structured by workflows, services and pages.
When you want to alter the standard Mobile WMS, you can easily modify responses on the device here. It is built into the app.
Looking at the count workflow you can see the different Id’s and if you for example want to change the validation of the location you add the <validationWarningType> and set the value to either <Block, None or Warn>.